This invention relates to bis(cyclopentadienyl) and bis(indenyl) ruthenium complexes which are useful in chemical vapor deposition (CV) and other procedures.
The state of the art relevant to this invention as of Jul. 17, 1997 is summarized in U.S. Pat. No. 6,002,036. A process for the synthesis of bis(alkylcyclopentadienyl) ruthenium complexes by treatment of RuCl3 hydrates and ethylcyclopentadiene or isopropylcyclopentadiene with zinc powder in an alcohol solvent at xe2x88x9230xc2x0 C. to 0xc2x0 C. is described.
The invention comprises synthesis of bis(cyclopentadienyl), bis(alkylcyclopentadienyl), bis(indenyl) or bis(alkylindenyl) liquid and solid ruthenium complexes by treating ruthenium trichloride hydrate and a cyclopentadienyl compound or an indenyl compound with magnesium powder in C2 to C8 alkanol, e.g., ethanol. The treating may be accomplished at a temperature from about 10xc2x0 C. to about xe2x88x9230xc2x0 C.
As used in this specification, the following terms have the meaning set forth:
(1) Cyclopentadienyl Compound
A compound of the formula 
in which each R is independently hydrogen or a C1 to C10 alkyl group. C1 to C5 monoalkyl cyclopentadienyl compounds are preferred.
(2) Indenyl Compound
A compound of formula 
in which each R is independently hydrogen or a C1 to C10 alkyl group. C1 to C5 monoindenyl compounds are preferred.
Ruthenium trichloride dihydrate, a cyclopentadienyl or indenyl compound, and an alkanol, preferably ethanol, are combined and treated with magnesium powder of about minus 100 (xe2x88x92100) to 200 mesh at low temperatures with an appropriate stir out. A bis(cyclopentadienyl) or bis(indenyl) ruthenocene may be isolated by filtration, followed by combination with an aliphatic or aromatic hydrocarbon solvent, preferably hexane or toluene, another filtration, and subsequent passage through a silica column. Final products, if solids, may be isolated in  greater than 99% purity in yields of about 65 weight percent by crystallization from a hydrocarbon solvent. High purity liquid products may be isolated by fractional distillation.